She did spend time with the only female detective in gritty East London to gather insight into her character. The two worked the tough housing projects in the area with no sign of firearms most Americans take for granted with their police force.

Her only past with firearms onscreen was the 2001 action project "51st State" with Samuel L. Jackson and Robert Carlyle.

"I was sorely miscast as the most dangerous woman in the universe," she laughs. "And I was this leather-clad assassin motorbike rider. I had to wield these AK-47s or whatever they area."

It was not a convincing performance. "I couldn't even hold the gun up for the length of time to shoot the scene," she admits. "Whenever they cut to me I was always resting it on a piece of furniture."